Proposals have been made on various techniques to be utilized in a personal digital assistant such as a cellular phone and a smartphone for a commercial transaction. As one of the above techniques, such a system is widely known in which a business operator transmits, from a server administered by the business operator per se to the personal digital assistant administered by a consumer, a benefit (coupon) relating to specific merchandise purchase or transmit settlement transaction information for performing settlement of a merchandise price, or the like. The consumer displays the transmitted benefit or settlement transaction information on a display of the personal digital assistant, or the like.
In addition, a means for providing information convenient for the transaction is not limited to displayed output on the display. For example, a configuration according to which the transaction information is transmitted and received by using a telecommunication means such as Bluetooth (registered trademark), Wi-Fi (registered trademark) and RFID is conceivable.
Moreover, JP 2013-141054 A discloses an art in which an ultrasonic wave is output inside a specific section to provide a personal digital assistant existing inside the section with transaction information contributing to a transaction such as a point return.
However, with regard to displayed output on a display, a third party photographs the display screen, thereby easily duplicating information. Moreover, in the case of a configuration of communicating transaction information by using various telecommunication means or the ultrasonic wave described in JP 2013-141054 A, a possibility of interference by another communication, interception from a third party or a codec analysis cannot be excluded.